Those involved with the development of binary arithmetic have required the need for mechanisms for finding the inverse of a number as easily as possible. Finding the inverse or reciprocal of a number has significance in different applications: for example, oftentimes, only the period of the occurrence is known; therefore, to determine the frequency in real time, the reciprocal of the period must be obtained. Methods for obtaining the frequency of an occurrence where only the period of the occurrence is known heretofore has required complex apparatus such as that taught by H. Ling in U. S. Pat. No. 3,633,018, issued Jan. 4, 1972; W. S. Bennett in U.S. Pat. No. 4,047,011, issued Sept. 6, 1977; and W. S. Bennett in U.S. Pat. No. 4,025,773, issued May 24, 1977, respectively. Ling teaches a reciprocal convergence technique for obtaining the reciprocal of a number. This technique requires complex nonmodular hardware to carry out the method. Bennett in his disclosures describes a method of performing division by successive approximations which similarly require complex circuitry.
The above-mentioned disclosures are generally applicable for use in large digital computer systems. Therefore, the inherent complexity of the aforementioned patented methods is a major deterrent to their use. But where the reciprocal of a binary number is needed in a relatively simple application, the previously mentioned methods may be too expensive or complex to implement. For example, the reciprocal of a number may be needed in conjuction with a simple heart rate monitor, or it may be needed for ocean study experiments to determine water velocity or the interaction between waves and the ship. This procedure can be utilized to generate a pseudorandom sequence, useful in the field of broadband communication and elsewhere. The complex circuitry disclosed in the above-mentioned patents would not be compatible with such a use.
The complexity of the circuitry may lend itself to problems which tend to limit the application of the methods described in the previously mentioned patents to a large system. It is known that there are various methods for producing the reciprocal of a binary number and that those methods are generally complex.
It is an object of this invention to provide a simpler apparatus for determining the reciprocal of a binary number than any known to the prior art.
In contrast to the prior art, this invention is adaptable to low-frequency occurrences. This hardware simplification is readily amenable to integrated circuit technology and clearly represents an improvement over the prior art.